@1dayatatime
What I understand from "closing the border" is a significantly restricting the level of legal migration resulting in a large reduction but not a "stop".
They mean stop people coming in.
illegal migration by definition is illegal and cannot so easily be stopped however it can be discouraged.
Illegal immigrants have overstayed their visas. It's not illegal to claim asylum in the UK.
So let's say we significantly restrict legal migration. On the point you raised about a reduction in the number of foreign students then Universities will find the adjustment hard, but they will have to focus on providing quality and good value education to UK students as they previously did rather than relying on ( or even exploiting) cash cow foreign students to balance their budgets.
All the best with that.
Let's take skill shortages- there are always skill shortages and redundant skills in any economy that's how the labour market works. Right now there's a shortage of brick layers and AI engineers and a surplus of say law graduates. But in sectors of shortage then wages rise and vice versa and people retrain - this is all perfectly normal.
If wages rise in sectors which have a shortage, why aren't the wages of nurses through the roof? We have a nursing crisis and import nurses from abroad.
We're importing labour not training people up because that means investment and the government aren't investing.
Yes there would be disruption in the short term as employers realise then can no longer use immigration as a low cost quick fix instead of using higher salaries and training.
There wouldn't be anyone who could fill essential roles in the NHS or to take jobs in the hospitality sector. I agree that we need to pay higher salaries but the argument against that is that businesses would push up prices and move out of the UK.
But it will avoid the long term cost of providing medical support and state pensions to those migrants in later years who have legitimately earned their right to and are perfectly entitled to these benefits by working in the UK and paying taxes.
This doesn't make sense.
We have more than enough people in the UK to perform all these roles, it's just that either UK nationals don't want to do them for the salaries offered or employers don't want to increase salaries to the levels demanded by UK nationals.
We don't have enough people of working age because of our low birth rate.